public override sealed void Update()

Systems should never override . Instead, implement system behavior in SystemBase.OnUpdate.

If a system manually calls another system's SystemBase.Update() method from inside its own SystemBase.OnUpdate method, EntityQuery objects in the caller system might see unexpected and incorrect change version numbers based on the processing performed in the target system. For this reason, you shouldn't manually update one system from another if both systems are processing entity data, especially if either uses EntityQuery.SetChangedVersionFilter. This guidance doesn't apply to ComponentSystemGroup or other "pass-through" systems which only update other systems without manipulating entity data.